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A Abeliovich C Chen Y Goda AJ Silva CF Stevens S Tonegawa 《Canadian Metallurgical Quarterly》1993,75(7):1253-1262
Calcium-phospholipid-dependent protein kinase (PKC) has long been suggested to play an important role in modulating synaptic efficacy. We have created a strain of mice that lacks the gamma subtype of PKC to evaluate the significance of this brain-specific PKC isozyme in synaptic plasticity. Mutant mice are viable, develop normally, and have synaptic transmission that is indistinguishable from wild-type mice. Long-term potentiation (LTP), however, is greatly diminished in mutant animals, while two other forms of synaptic plasticity, long-term depression and paired-pulse facilitation, are normal. Surprisingly, when tetanus to evoke LTP was preceded by a low frequency stimulation, mutant animals displayed apparently normal LTP. We propose that PKC gamma is not part of the molecular machinery that produces LTP but is a key regulatory component. 相似文献
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J Stevens 《Canadian Metallurgical Quarterly》1998,40(7):469-471
OBJECTIVE: To determine the actual use of 'statin' therapy for primary and secondary prevention and the potential effect of using the Sheffield Table for primary prevention of coronary heart disease upon 'statin' use in a consultant-run Hypertension and Cardiovascular Risk Clinic. DESIGN: Prospective audit of the current use of cholesterol-lowering therapy and the effect of implementing the criteria used in the Sheffield Table and the Scandinavian Simvastatin Study for cholesterol lowering in 'at risk' patients upon statin use in a consultant-led cardiovascular risk clinic. SETTING: The Aberdeen Hypertension Clinic. RESULTS: A total of 1500 patients were reviewed of which 416 (27.7%) had experienced at least one clinical manifestation of atherosclerotic cardiovascular disease (CVD) and 392 (94%) of these had a total cholesterol measured of whom 298 (76%) had a total cholesterol >5.5 mmol/l. Only 11.2% of eligible patients were actually receiving lipid-lowering treatment for secondary prevention. A total of 1084 patients with no prior cardiovascular disease were identified, 97 (8.9%) were excluded because of age. Using the Sheffield Table, 92 (9.4%) of these patients were eligible for statin therapy and only six of the 92 patients were actually receiving treatment. CONCLUSIONS: The results of this study reveal that even in a consultant-led cardiovascular prevention clinic there is a significant discrepancy between optimal evidence-based management and the actual delivery of clinical care. Seventy-two per cent and 9.3% of patients attending the clinic were eligible for statin treatment for secondary and primary prevention, respectively. However, only 11.2% of patients suitable for secondary prevention and 6.5% of patients suitable for primary prevention were actually receiving appropriate lipid-lowering therapy. Considering the proven benefit of this form of medical intervention the results of this study are of real importance to practising clinicians and patients alike. 相似文献
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CF Wippermann RG Huth FX Schmidt J Thul M Betancor D Schranz 《Canadian Metallurgical Quarterly》1996,22(5):467-471
OBJECTIVE: To compare a system that continuously monitors cardiac output by the Fick principle with measurements by the thermodilution technique in pediatric patients. DESIGN: Prospective direct comparison of the above two techniques. SETTING: Pediatric intensive care unit of a university hospital. PATIENTS: 25 infants and children, aged 1 week to 17 years (median 10 months), who had undergone open heart surgery were studied. Only patients without an endotracheal tube leak and without a residual shunt were included. METHODS: The system based on the Fick principle uses measurements of oxygen consumption taken by a metabolic monitor and of arterial and mixed venous oxygen saturation taken by pulse- and fiberoptic oximetry to calculate cardiac output every 20s. INTERVENTIONS: In every patient one pair of measurements was taken. Continuous Fick and thermodilution cardiac output measurements were performed simultaneously, with the examiners remaining ignorant of the results of the other method. RESULTS: Cardiac output measurements ranged from 0.21 to 4.55 l/min. A good correlation coefficient was found: r2 = 0.98; P < 0.001; SEE = 0.41 l/min. The bias is absolute values and in percent of average cardiac output was - 0.05 l/min or - 4.4% with a precision of 0.32 l/min or 21.3% at 2 SD, respectively. The difference was most marked in a neonate with low cardiac output. CONCLUSION: Continuous measurement of cardiac output by the Fick principle offers a convenient method for the hemodynamic monitoring of unstable infants and children. 相似文献
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Scientific co-operation in Europe and the citation of multinationally authored papers 总被引:3,自引:1,他引:2
Under the sponsorship of the U.S. National Science Foundation, CHI Research, Inc. developed the bibliometric indicators for the U.S. National Science Board'sScience Indicators Reports starting withScience Indicators 1972. In the work reported here, for the Commission of the European Communities, CHI has extended the Science Indicators techniques and database to a study of publication, coauthorship and citation within 28 scientific fields related to various European Community programs.Perhaps the most important finding of the research was that internationally coauthored papers — papers authored by scientists affiliated with institutions in more than one EC country — were cited two times as highly as papers authored by scientists working at a single institution within a single country. These EC-EC internationally coauthored papers were cited as highly as EC-Non EC and Non-EC papers. This indicates that the internationally linked European science is of as high impact as any other science in the world.A second key finding was that, after compensating for national scientific size, the degree of international coauthorship did not appear to be particularly dependent upon size. However, linguistic and cultural factors were found to be very strong. The patterns of coauthorship amongst the European countries are far from homogeneous, and are quite heavily affected by linguistic, historical, and cultural factors.Finally, it was found that international coauthorship is increasing steadily, both within and outside of the Community, with some evidence that international cooperation is increasing more rapidly in scientific fields that have been targeted by the Commission.This work has been sponsored by the MONITOR programme of the Commission of the European Communities. 相似文献
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Stevens M. Williams P.D. Peterson G.L. Kurkowski S.H. 《Computational Intelligence Magazine, IEEE》2008,3(2):65-68
This research supports the hypothesis that the Trust Vector model can be modified to fit the CyberCraft Initiative, and that there are limits to the utility of historical data. This research proposed some modifications and expansions to the Trust Model Vector, and identified areas for future research. 相似文献
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